This container can be pulled via:
  docker pull registry.opensuse.org/virtualization/containerfile/kubevirt/virt-controller:1.6.3
  docker pull registry.opensuse.org/virtualization/containerfile/kubevirt/virt-controller:1.6.3-Virt.1699.212.17
  docker pull registry.opensuse.org/virtualization/containerfile/kubevirt/virt-controller:1.6.3.Virt.1699.29.708

Set DOCKER_CONTENT_TRUST=1 to enable image tag verification.